Dual site control of cardiac alternans in 1D human ventricular tissue

Alternans are precursors to ventricular fibrillation (VF), a dangerous cardiac arrhythmia that can lead to sudden cardiac death (SCD). Effective suppression of alternans is therefore crucial in preventing the onset of VF. Numerical simulations have shown that alternans in 1D cardiac tissues longer than about 1 cm cannot be controlled by a variety of electrical-based methods using single site control (SSC). Here, we investigate the possibility of controlling small and large alternans in 1D human ventricular tissues longer than 1 cm using dual site control (DSC). Two electrical-based control methods, Proportional Feedback Control (PFC) and Constant Feedback Control (CFC), are studied and compared. The additional independent control site in DSC overcomes the length limitation of SSC, enabling the two methods to control the alternans in tissues longer than 1 cm, up to 8 cm. Even for a 1 cm tissue, DSC is more effective for alternans control than SSC. Of the two control methods, PFC is more effective and robust than CFC; however, CFC is easier to implement in practice because it does not require precise action potential duration (APD) measurements. Our findings suggest that multi-site control of alternans could be effective in a 3D human ventricular model (where SSC is quite certain to fail)-this would provide a potential clinical strategy for preventing VF using electrical stimulation.